Rigidity — Generally, rigidity refers to inflexibility or resistance to change. It has a number of specific meanings depending on the field of application.In medicine (neurology) rigidity describes an increase in muscle tone, leading to a resistance to… … Wikipedia

shear modulus — Physics. a coefficient of elasticity of a substance, expressing the ratio between the force per unit area (shearing stress) that laterally deforms the substance and the shear (shearing strain) that is produced by this force. Also called modulus… … Universalium